Closure device and method for tissue repair

ABSTRACT

A method of closing a tissue wound includes providing a wound closure device having a first anchor, a second anchor, and a flexible member movably attached to the second anchor, positioning the first anchor against tissue, passing the flexible member across the wound, positioning the second anchor against tissue, and pulling on a free end of the flexible member to shorten a length of the flexible member between the first and second anchors, thereby closing the wound. A wound closure device includes a first anchor, a second anchor; and a flexible member connecting the first anchor to the second anchor, the flexible member being movably attached to the second anchor, such that pulling on a free end of the flexible member shortens a length of the flexible member between the first and second anchors.

BACKGROUND

This application is a continuation of co-pending U.S. application Ser.No. 09/704,926, filed Nov. 2, 2000, entitled CLOSURE DEVICE FOR ANDMETHOD FOR TISSUE REPAIR, and a continuation-in-part of co-pending U.S.application Ser. No. 09/453,120, filed Dec. 2, 1999, entitled WOUNDCLOSURE DEVICES AND METHODS.

The invention relates to a closure device and method for tissue repair.

Fibrous tissue wounds, such as muscle, ligament, and cartilage tears,can be repaired arthroscopically using sutures. Traditionally, to closea fibrous tissue wound, a surgeon would insert two suture needles intothe tissue with sutures attached, thread the sutures across the wound,and then tie knots to fix the free ends of the sutures within thetissue.

To simplify the wound closure procedure and to improve fixation, varioustypes of suture anchors have been developed. One example of a sutureanchor is disclosed in Hayhurst, U.S. Pat. No. 4,741,330, which isincorporated herein by reference. In Hayhurst, one end of a suture isfixed to a resiliently-deformable, bar-shaped suture anchor. The anchoris loaded into the bore of a hollow needle and deployed into or againstthe fibrous tissue. The surgeon then threads the suture across the woundand tensions a free end of the suture to pull the wound closed. When thesurgeon tensions the suture, the bar in the anchor becomes orientedtransversely to the suture hole, anchoring the suture in place.

SUMMARY

According to one aspect of the invention, in general, the inventionfeatures a wound closure device that includes a first anchor, a secondanchor, and a flexible member that connects the first anchor to thesecond anchor. The flexible member is movably attached to the secondanchor, such that pulling on a free end of the flexible member shortensa length of the flexible member between the first and second anchors.

Embodiments of this aspect of the invention may include one or more ofthe following features.

The movable attachment of the flexible member to the second anchorallows the length of the flexible member between the first and secondanchors to be shortened, but not lengthened.

The movable attachment can be a knot formed in the flexible member atthe second anchor. The knot includes, e.g., a first portion of theflexible member that forms a loop, and a second portion (which mightinclude the free end) that passes over a surface of the second anchorand through the loop. The surface can be, e.g., an exterior surface ofthe second anchor.

Pulling on the free end of the flexible member in one direction causesthe flexible member to slide through the loop, but pulling on theflexible member in an opposite direction causes the loop to press thesecond portion against a compression surface of the second anchor,resisting increase in the length of the flexible member between thefirst and second anchors. The loop can be disposed within a partiallyenclosed region of the second anchor.

The second anchor can include a first section that defines a pluralityof holes through which the first portion of the flexible member passesto form the loop. A second section of the second anchor defines apassage that connects to the partially enclosed region, and the free endof the suture passes through this passage.

The second anchor can include a rounded body and an appendage attachedto the rounded body, where the rounded body and the appendage define apartially enclosed region therebetween. At least a portion of theflexible member passes through the partially enclosed region. Inaddition, the flexible member might wrap around the rounded body.

The rounded body can have a generally cylindrical shape, sized to fitwithin the bore of a hollow needle, and an axial groove. The grooveextends across an axial length of the rounded body. The cross-sectionalshape of the rounded body can be, e.g., a rectangle, an L, or a D.

The second anchor can also have a generally hemispherical shape, agenerally crescent shape, or a T-shape. The crescent-shaped anchor canhave sharp tip configured to penetrate tissue.

The second anchor defines a through-hole through which the flexiblemember passes. In addition, the device can also include a secondflexible member that passes through the through-hole, where the secondflexible member has a thickened portion that has a width greater than awidth of the through-hole, such that the thickened portion cannot passthrough the through-hole.

The first anchor includes, e.g., a generally cylindrical body sized andshaped to fit within the bore of a hollow needle, and a projection, suchas a longitudinal fin, extending from the cylindrical body.Alternatively, the first anchor can have a button shape. The firstanchor can define a hole for passage of the flexible membertherethrough, and the flexible member can be fixed to the first anchor.

The flexible member can be a suture.

The wound closure device further includes a retaining element coupled tothe flexible member. The retaining element is slidably received by theflexible member and acts to limit loosening of the flexible memberrelative to the second fixation member. Alternatively, the retainingelement is movable relative to the second fixation member and acts tolimit loosening of the flexible member relative to the second fixationmember.

In another aspect, the invention features a wound closure kit thatincludes an open-tipped needle and first and second anchors connected bya flexible member disposed within a bore of the needle.

Embodiments of this aspect of the invention may include one or more ofthe following features.

The needle can define a longitudinal slit, and the first anchor caninclude a projection that protrudes through the slit. The second anchorcan also include an appendage that protrudes through the slit, and theflexible member can be attached to the appendage. The flexible membercan be fixed to the first anchor, but movably attached to the secondanchor.

In another aspect, the invention features a method of closing a tissuewound. The method includes: (a) providing a wound closure device thathas a first anchor, a second anchor, and a flexible member movablyattached to the second anchor; (b) positioning the first anchor againsttissue; (c) passing the flexible member across the wound; (d)positioning the second anchor against tissue; and (e) pulling on a freeend of the flexible member to shorten a length of the flexible memberbetween the first and second anchors, thereby closing the wound.

This aspect of the invention may include one or more of the followingfeatures.

The flexible member can be slidably attached to the second anchor by aone-way knot, such that after completion of the pulling step, the lengthof the flexible member between the first and second anchors remainsshortened. Part of the one-way knot can be disposed within a partiallyenclosed region of the second anchor. The partially enclosed region canbe located such that during the pulling step, the portion of the one-wayknot disposed within the partially enclosed region avoids contact withtissue.

The first positioning step can include positioning the first anchor on afirst side of the wound. The passing step can include passing theflexible member from the first side to a second side of the wound,engaging tissue on the second side, and returning the flexible member tothe first side. The second positioning step can include positioning thesecond anchor on the first side of the wound.

The first and second anchors can initially be disposed, at leastpartially, within the bore of a hollow, open-tipped needle. The firstanchor can include a section that protrudes through a slit in theneedle, and the first positioning step can include engaging theprojection with tissue to remove the first anchor from the bore.

The providing step can include providing a device in which the flexiblemember passes through a through-hole in the second anchor, and thedevice further includes a second flexible member that also passesthrough the through-hole. The second flexible member has a thickenedportion that is wider than the through hole. The method further includespulling the second flexible member until the thickened portion wedgesinto the through hole.

In another aspect, the invention features a method of repairing a tearin a meniscus. The method includes: (a) providing a tear closing devicehaving a first anchor, a second anchor, and a flexible member movablyattached to the second anchor; (b) positioning the first anchor againstthe meniscus; (c) passing the flexible member across the tear; (d)positioning the second anchor against the meniscus; and (e) pulling on afree end of the flexible member to shorten a length of the flexiblemember between the first and second anchors, thereby closing the tear.

Embodiments of this aspect of the invention can include one or more ofthe following features.

The first positioning step can include positioning the first anchoragainst an external surface of the meniscus, on a first side of thetear, the passing step can include passing the flexible member from thefirst side to a second side of the tear, engaging tissue on the secondside, and returning the flexible member to the first side, and thesecond positioning step can include positioning the second anchoragainst the external surface. Alternatively, the first and secondanchors can be positioned against external surfaces of the meniscus onopposite sides of the tear.

According to another aspect of the invention, a surgical method includespositioning a fixation member relative to tissue, moving a flexiblemember coupled to the fixation member relative to the fixation member tobring two tissue surfaces together, and moving a retaining elementcoupled to the flexible member relative to the fixation member. Theretaining element acts to limit loosening of the flexible memberrelative to the fixation member.

Embodiments of this aspect of the invention may include one or more ofthe following features.

The step of moving the flexible member comprises pulling the flexiblemember. The step of moving the flexible member also accomplishes thestep of moving the retaining element, which is, for example, a slipknot. Alternatively, the step of moving the retaining element includesmoving the retaining element relative to the flexible element. Theretaining element is, for example, a friction element which permitssliding of the retaining element relative to the flexible element inonly one direction. In another illustrated embodiment the retainingelement is in the form of an overhand knot, and the method includesadvancing the overhand knot along the flexible element. In anotherillustrated embodiment, the retaining element is in the form of aChinese trap.

In an exemplary embodiment, the step of moving the flexible memberincludes pulling on only one end of the flexible member.

In another illustrated embodiment, the method includes positioning asecond fixation member relative to the tissue. The second fixationmember is coupled to the flexible member, either movably or fixedly. Thestep of moving the flexible member includes, for example, pulling on twoends of the flexible member or pulling on only one end of the flexiblemember.

The step of positioning the fixation member includes positioning thefixation member on an outer surface of the tissue, and the two tissuesurfaces brought together are both soft tissue. Alternatively, thefixation member is positioned in a bone hole, and one of the two tissuesurfaces brought together is bone and the other soft tissue.

In another illustrated embodiment, the step of positioning the fixationmember includes passing the fixation member through a loop of theflexible member. The loop is positioned within a tear in soft tissue.

According to another aspect of the invention, a method for repairing atear in soft tissue includes advancing a fixation member coupled to aflexible member through tissue on either side of the tear and through aloop of the flexible member, and tensioning the flexible member to bringtwo tissue surfaces on either side of the tear together.

Embodiments of this aspect of the invention may include one or more ofthe following features. The loop is positioned within the tear. Themethod includes pulling an end of the flexible member to bring the twotissue surfaces together. The fixation member is in the form of a barbedmember.

According to another aspect of the invention, an apparatus for repairinga tear in soft tissue includes at least two fixation members, a flexiblemember substantially immovably secured to the first fixation member andmovably coupled to the second fixation member, and a retaining elementcoupled to the flexible member. The retaining element is movablerelative to the second fixation member and acts to limit loosening ofthe flexible member relative to the fixation member.

According to another aspect of the invention, an apparatus for repairinga tear in soft tissue includes at least two fixation members, a flexiblemember substantially immovably secured to the first fixation member andmovably coupled to the second fixation member, and a retaining elementcoupled to the flexible member. The retaining element is slidablyreceived by the flexible member and acts to limit loosening of theflexible member relative to the fixation member.

According to another aspect of the invention, an apparatus for repairinga tear in soft tissue includes a fixation member, and a flexible membermovably coupled to the fixation member. A first end of the flexiblemember is looped back and secured to the flexible member to form a loop.The loop is remote from the fixation member.

According to another aspect of the invention, a flexible member holderincludes a shaft, a first tine at an end region of the shaft defining afirst region for receiving a first portion of a loop of a flexiblemember, and a second tine at the end region of the shaft defining asecond region for receiving a second portion of the loop of the flexiblemember.

Embodiments of this aspect of the invention may include one or more ofthe following features. The shaft is a tube. The first and secondregions are grooves.

According to another aspect of the invention, a device for repairing atear in a tissue includes a needle having a distal region definedbetween two holding elements, and a proximal region. A first fixationmember is positioned within the distal region and a second fixationmember is positioned within the proximal region. A flexible member iscoupled to the first and second fixation members.

Embodiments of this aspect of the invention may include one or more ofthe following features. A first of the holding elements is a crimp inthe needle in the distal region, and the second holding element is adimple or ramp extending into a lumen of the needle. The needle wall hasa slot and the fixation members extend through the slot. The needle issized to fit into an end of a protector tube. A push pin is sized to fitinside the needle.

Embodiments of the invention may include one or more of the followingadvantages. The first and second anchors can be deployed using a singlehollow needle, rather than two separate needles. After deploying afixation member or anchor, the surgeon need not tie an additional knot.The length of a flexible member coupled to the fixation member can beadjusted after deploying the fixation member, allowing a surgeon to setthe tension in the flexible member to a desired level. The length of aflexible member spanning across a tear in tissue can be shortened toclose the tear by tensioning the flexible member with no additionalmanipulation being required to limit loosening of the flexible member.

Since the device uses a flexible member, such as a suture, to close thetissue wound, rather than inflexible staples or tacks, the tissue is notsignificantly damaged when it expands and contracts. For example, if thesoft tissue is a meniscus, the fixation members do not damage themeniscal tissue when the knee moves.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent form thedescription and drawings, and from the claims.

DESCRIPTIONS OF DRAWINGS

FIG. 1 is an illustration of a closure device according to theinvention, shown mending a tear in soft tissue;

FIGS. 2A-2I show a method of tying a slip knot in suture of the closuredevice of FIG. 1;

FIG. 3 is a perspective view of a delivery device for inserting theclosure device of FIG. 1 into soft tissue;

FIG. 4 is a perspective view of the delivery device of FIG. 3 shown withan outer sheath removed;

FIG. 4A is a perspective view of a fixation member of the closure deviceof FIG. 1;

FIG. 4B is a cross-sectional end view of the delivery device of FIG. 4,taken along lines 19B-19B;

FIG. 4C is a cross-sectional side view of an alternative embodiment of aneedle of the delivery device of FIG. 3;

FIG. 5 is side view of the delivery device of FIG. 3;

FIG. 5A is a side view of a variable length depth stop for use with thedelivery device of FIG. 3;

FIG. 5B is a perspective view of a cannula for use with the deliverydevice of FIG. 3;

FIGS. 6-11 show the delivery device in use inserting the closure deviceof FIG. 1 in soft tissue, with FIG. 7 being an exploded view of region 7of FIG. 6;

FIG. 12 is an illustration of the closure device of FIG. 1 with analternative embodiment of a retaining element, shown mending a tear insoft tissue;

FIGS. 12A and 12B show alternative embodiments of the retaining elementof FIG. 11;

FIG. 12C shows the retaining element of FIG. 12 in an alternativeposition;

FIG. 13 shows an additional alternative embodiment of a retainingelement in the form of an overhand knot;

FIGS. 13A and 13B show an overhand knot and a knot pusher for advancingthe overhand knot of FIG. 13;

FIG. 14 is an illustration of an alternative embodiment of a closuredevice;

FIG. 14A shows an alternative arrangement of the closure device anddelivery device of FIG. 14;

FIG. 14B is an illustration of an alternative embodiment of a closuredevice;

FIG. 15 is an illustration of an alternative embodiment of a closuredevice for use in attaching soft tissue to bone;

FIG. 16A is a perspective view of a wound closure device;

FIG. 16B is a side view of a first suture anchor of the wound closuredevice of FIG. 16A;

FIG. 16C is a side view of a second suture anchor of the device of FIG.16A;

FIG. 16D is an enlarged view of a braided suture;

FIG. 17 is a perspective, cut-away view of the wound closure device ofFIG. 17A implanted within a meniscus;

FIGS. 18A and 18B are sectional views of the second suture anchor andone-way knot of the wound closure device of FIG. 16A;

FIG. 19 is a perspective view of a hollow needle, with the wound closuredevice of FIG. 16A disposed within a bore of the needle;

FIGS. 20A-20D are schematics illustrating deployment of the woundclosure device of FIG. 16A into a meniscus using a plunger;

FIGS. 21A-21D are schematics illustrating deployment of the woundclosure device of FIG. 16A into a meniscus using a plunger and a spacer;

FIG. 22A is a perspective view of an alternative first anchor design fora wound closure device, used in reverse deployment of the device;

FIGS. 22B-22E are schematics illustrating reverse deployment of a woundclosure device;

FIGS. 23A and 23B are perspective views of the second suture anchor ofFIGS. 16A and 16C, showing an alternative one-way knot configuration forthe anchor;

FIGS. 24-27 are sectional views of alternative configurations of thesuture anchor and one-way knot of FIGS. 18A and 18B;

FIG. 28A is a top view of a T-shaped second suture anchor;

FIG. 28B is a side view of the T-shaped suture anchor of FIG. 28A;

FIG. 28C is a front view of a crescent-shaped second suture anchor;

FIG. 28D is a side view of the crescent-shaped suture anchor of FIG.13C;

FIGS. 29-31 are sectional views showing deployment of wound closuredevices that include the crescent-shaped suture anchor of FIG. 28C;

FIG. 32 is a perspective, partially schematic view of an alternativewound closure device implanted within a meniscus;

FIG. 33A is a perspective view of an alternative first suture anchordesign for a wound closure device;

FIG. 33B is a perspective, cut-away view of the wound closure device ofFIG. 33A implanted within a meniscus;

FIG. 34 is a cross-sectional side view of an alternative embodiment of aclosure device, shown mending a tear in soft tissue;

FIG. 35 shows the closure device of FIG. 34 in use prior to securing theclosure device in place;

FIG. 36 is a top view of the closure device of FIG. 34, shown aftersecuring the closure device in place;

FIG. 37 is a side view of a delivery device for inserting the closuredevice of FIG. 34 in soft tissue;

FIG. 37A is a perspective view of a distal section of the deliverydevice of FIG. 37 shown with a fixation member of the closure device ofFIG. 34;

FIG. 37B is a perspective view similar to that of FIG. 37A shown withthe closure device of FIG. 34;

FIG. 37C is an illustration of the closure device of FIG. 34;

FIGS. 38-40 show the delivery device of FIG. 37 in use inserting theclosure device of FIG. 34 in soft tissue;

FIG. 41 is a cross-sectional side view of the closure device of FIG. 34with an alternative embodiment of a retaining element, shown mending atear in soft tissue;

FIG. 42 is a cross-sectional side view of an alternative embodiment of aclosure device, similar in use to the closure device of FIG. 34; and

FIGS. 43 and 44 are alternative embodiments of a fixation member of theclosure device of FIG. 34.

DETAILED DESCRIPTION

Referring to FIG. 1, a closure device 8 for mending a tear 12 in softtissue 14, e.g., meniscus of the knee joint, includes a flexible member,e.g., suture 10, coupled to a first fixation member 16 and a secondfixation member 18. Suture 10 is fastened to fixation member 16 to limitmovement of suture 10 relative to fixation member 16, while suture 10 ismovable relative to fixation member 18.

When implanted in the knee joint, fixation members 16 and 18 lie on asurface 20 of tissue 14, for example, the outer surface of the meniscus.Suture 10 has a first suture length 10 a extending from first fixationmember 16 through tissue 14, traversing tear 12, and emerging at asurface 26 of tissue 14; a second suture length 10 b extending acrosssurface 26; a third suture length 10 c extending back through tissue 14,traversing tear 12 at a location spaced from first length 10 a, andemerging at tissue surface 20 where suture 10 loops through secondfixation member 18; and a fourth suture length 10 d extending fromsecond fixation member 18 through tissue 14, traversing tear 12, andemerging at surface 26. Suture 10 has a free end 30 which the surgeonpulls, in the direction of arrow 32, to bring sides 22, 24 of tear 12together into juxtaposition (as shown in FIG. 10).

As described further below, suture portion 10 c and suture portion 10 dare tied together prior to implantation of device 8 to form a retainingelement in the form of a slip knot 28 that allows suture 10 to be pulledin the direction of arrow 32, but does not allow tension on suture 10 topull suture 10 in the opposite direction, which would allow tear 12 tore-open.

Referring to FIGS. 2A-2I, prior to insertion into tissue 14, suture 10is attached to fixation members 16, 18 and slip knot 28 is formed.Fixation member 16 defines holes 16 a, 16 b for receiving suture 10, andfixation member 18 defines holes 18 a, 18 b for receiving suture 10. Asillustrated in FIGS. 2A-2D, suture 10 is attached to fixation member 16by threading suture 10 through a needle 50, and passing needle 50 andsuture 10 through holes 16 a, 16 b in fixation member 16 (FIG. 2A).Suture 10 now defines a long suture section 52 and a short suturesection 54. Long suture section 52 is then attached to short suturesection 54 by passing needle 50 and long suture section 52 through shortsuture section 54 at a region 56 (FIG. 2B). Pulling long suture section52 away from fixation member 16 (FIG. 2C) then draws region 56 towardfixation member 16 forming a knot 60 (FIG. 2D). Suture 10 is now securedto fixation member 16.

Referring to FIGS. 2E-2I, suture 10 is now attached to fixation member18 by passing long suture section 52 through holes 18 a, 18 b in secondfixation member 18 (FIG. 2E). Long suture section 52 now defines a firstsuture length 62 and second suture length 64. Slip knot 28 is formed bypassing fixation member 16 under suture length 64, over suture length64, and under suture length 62, forming a loop 66 (FIG. 2F); thenpassing fixation member 16 over suture lengths 62 and 64, forming a loop68 (FIG. 2G); and then passing fixation member 16 under suture lengths64 and 62 (FIG. 2G), and finally through loop 68 (FIG. 2H). Pullingfixation member 16 relative to fixation member 18 tightens slip knot 28(FIG. 2I). Pulling free end 30 of suture 10 now acts to slide suture 10through slip knot 28, while slip knot 28 limits sliding of suture 10 inthe opposite direction when suture 10 is under tension.

Referring to FIG. 3, a delivery device 99 for implanting device 8 intissue 14 includes a sheath 200 and a needle 100. Sheath 200 ispreferably formed from plastic, and needle 100 is preferably metal.Needle 100 has an open distal end 111 with a pointed, tissue piercingtip 108. Needle 100 has an inner surface 102 defining a lumen 104 and aslot 110 both extending to open distal end 111. Slot 110 extends from anouter surface 106 of needle 100 to lumen 102. As described furtherbelow, needle 100 receives fixation member 16 and 18 within lumen 104and slot 110 with suture 10 tied to fixation members 16, 18 asillustrated in FIGS. 2A-2I. Sheath 200 defines a lumen 202 whichreceives needle 100 and device 8 with suture 10 positioned betweenneedle 100 and sheath 200 and extending through a hole 201 defined at aproximal end 203 of sheath 200. Sheath 200 has a distal end 202 fromwhich needle 100 extends.

Referring also to FIGS. 4-4B, slot 110 has a proximal, closed end 120and a distal open end 140. Fixation members 16 and 18 (which aregenerally described in U.S. Ser. No. 09/453,120, supra) have the sameshape with each fixation member including a cylindrical region 151received within lumen 104 of needle 100, and a fin 152 extending throughslot 110 with a portion 154 of fin 152 extending beyond outer surface106 of needle 100. Fixation member 16 is located at a distal region 112of slot 110, and fixation member 18 is located at a proximal region 114of slot 110. Distal end 111 of needle 100 is indented, for example,crimped at 150, and inner surface 102 of needle 100 has a protrusionextending into lumen 104, for example, a dimple 130, near distal end140. Dimple 130 and crimp 150 are sized to resist unintentional passageof the fixation members either over dimple 130 or through open distalend 111, though only a small force on the fixation members is needed toovercome the resisting load applied to the fixation members by crimp 150and dimple 130. Fixation members 16, 18 have sloped surfaces 152 a whichaid in passage through tissue, and a flat surface 154 a which aid inretention of the fixation member at their deployment sites.

During manufacturing, to position fixation members 16, 18 in needle 100,after suture 10 is attached to fixation members 16, 18, fixation member18 is loaded in needle 100 by passing fixation member 18 through distalend 111 and sliding fixation member 18 along lumen 104 and slot 110 toproximal end 120 of slot 110. Fixation member 16 is then loaded inneedle 100 by passing fixation member 16 through distal end 111 andpositioning fixation member 16 in region 112. Dimple 130 and crimp 150are then formed. Fixation member 16 is now restrained from unintentionalmovement in the proximal direction by dimple 130 and in the distaldirection by crimp 150. Alternatively, as shown in FIG. 4C, rather thandimple 130, a needle 100 a includes a ramp 130 a formed by making threeslits in a wall 101 of needle 100 a and bending a section of the walltoward the inside of the needle.

Referring also to FIG. 5, needle 100 has a proximal end 160 mounted to ahandle 180. Located within needle 100, proximal of fixation member 18,is a push rod 170 (FIG. 4) used to advance fixation member 18, asdescribed below. Handle 180 includes an actuating slider 190 attached topush rod 170 for advancing push rod 170. Once device 8 is secured toneedle 100, as described above, sheath 200 is placed over needle 100,with the majority of suture 10 located within and protected by sheath200. Sheath 200 also covers the majority of fixation member 18 and helpskeep fixation member 18 in position. Sheath 200 is then secured tohandle 180 by an interference fit. The distance needle 100 extends fromsheath 200 determines the penetration depth of needle 100 into thetissue. Delivery device 99 is supplied to the surgeon with device 8pre-loaded in needle 100.

Referring to FIG. 5A, an outer protective tube 200 a can be placed oversheath 200. Tube 200 a protects the needle tip during shipping. If it isdesired to supply the surgeon with a variable length depth stop, tube200 a can be provided with gradations 201. The surgeon scores tube 200 ato provide the tube with the desired length for the surgical procedure.Tube 200 a is coupled to handle 190 by a loose interference fit to allowthe surgeon to remove tube 200 a if tube 200 a is not being used duringsurgery.

Referring to FIG. 5B, to eliminate the need for placement of deliverydevice 99 through an arthroscopy cannula, a removable cannula 202 a,formed, for example, of a plastic material, can be placed over sheath200. Cannula 202 a has a distal, tissue penetrating tip 203 a and a slot204 a extending from a proximal end 205 a of cannula 202 a to withinabout 0.02 inches of distal tip 203 a to define a distal region 206 a.Slot 204 a permits the removal of cannula 202 a from delivery device 99after placement of the delivery device in the joint. To remove cannula202 a, the surgeon grasps the cannula and moves it laterally relative tosheath 200, until sheath 200 slides through slot 204 a. The surgeon thenpulls cannula 202 a proximally, which breaks cannula region 206 a,permitting complete removal of cannula 202 a.

Referring to FIGS. 6-11, in use, preferably under arthroscopic guidance,the user inserts delivery device 99 into, for example, the knee joint,and passes needle 100 through soft tissue 14 and across tear 12, untilneedle tip 108 and fixation member 16 extend through tissue surface 20.Dimple 130 prevents fixation member 16 from sliding proximally inresponse to forces acting on fixation member 16 during insertion throughtissue 14. Fixation member 16 is now positioned with flat, tissue facingsurface 154 a of portion 154 of fin 152 extending beyond needle surface106 engaging tissue surface 20 (FIG. 7). The user then pulls deliverydevice 99 proximally removing needle 100 from tissue 14 (FIG. 8). Theforce of the engagement of fixation member 16 with tissue surface 20during removal of needle 100 overcomes the retention force of crimp 150.Fixation member 16 slides distally out of open end 111 of needle 100 andremains at surface 20. During the retraction of needle 100, a portion ofsuture 110 with knot 28 is played out of delivery device 99, with suture10 extending through soft tissue 14 across tear 12.

The user then advances slider 190, advancing rod 170 to push fixationmember 18 distally, over dimple 130, to reside in region 112 betweendimple 130 and crimp 150 (FIG. 9). The user then moves needle 100 to aspaced location to the side of exit point 229 of suture 10 from tissue14, and re-inserts needle 100 into soft tissue 14, across tear 12, andthrough surface 20, until needle tip 108 and fixation member 18 extendthrough tissue surface 20 (FIG. 10). The user then pulls delivery device99 proximally removing needle 100 from tissue 14 (FIG. 11). The force ofthe engagement of fixation member 18 with tissue surface 20 duringremoval of needle 100 overcomes the retention force of crimp 150 suchthat fixation member 18 slides distally out of open end 111 of needle100 and remains at surface 20, as described above with reference tofixation member 16.

Free end 30 of suture 10 extends from sheath 200, as shown in FIG. 11.The user grasps free end 30 of suture 10 with forceps or by hand andpulls on free end 30 of suture 10. This shortens the length of suturebetween fixation members 16 and 18 (suture portions 10 a-10 c), bringingsides 22, 24 of tear 12 into juxtaposition, as shown in FIG. 11. Whenfree end 30 of suture 10 is pulled, slip knot 28 moves closer tofixation member 18. Depending on the length of suture between fixationmembers 16 and 18, slip knot 28 will either be on tissue surface 26 ormove within tissue 14. Slip knot 28 allows suture 10 to slide in thedirection of arrow 32, but does not allow suture 10 to slide in theopposite direction. The tension placed on suture 10 by pulling on thesuture relative to fixation members 16, 18, acts to turn the fixationmembers such that their long sides 255 are in contact with tissuesurface 20. Excess suture 10 can then be cut off. Further manipulationof suture 10 is not needed to secure fixation members 16, 18, althoughthe surgeon may wish to provide additional fastening as a back-upsecurement measure.

Referring to FIG. 12, rather than a slip knot 28 acting as a retainingelement allowing suture 10 to be tightened while resisting loosening ofsuture 10, here, a separate retaining element 210 is positioned on freeend 30 of suture 10. While pulling on free end 30, the surgeon advancesretaining element 210 through tissue 14, in the direction of arrow 212,until retaining element 210 is positioned against fixation member 18, asshown in dashed line. This action acts to close tear 12 and securedevice 8 in place.

Retaining element 210 defines a through bore 216 for receiving suture10. The material of retaining element 210, e.g., acetal, is selected,and the diameter of through bore 216 is sized relative to suture 10 toprovide the desired amount of friction between suture 10 and retainingelement 210 for adequate securement. Thus, the user can slide suture 10in the direction of arrow 212, but adequate friction is provided betweensuture 10 and retaining element 210 to limit sliding of retainingelement 210 in the opposite direction under normal loads in the kneejoint.

Referring to FIG. 12A, a retaining element 210 a defines two angledchannels 218, 220 for receiving free end 30 of suture 10. Retainingelement 210 a has a generally cylindrical surface 221 and ends 222, 223.Channel 218 has a first opening 224 at end 222 and second opening 225 onsurface 221. Channel 220 has a first opening 226 at end 223 and a secondopening 227 on the same side of surface 221 as channel 218. Suture 10follows a tortuous path through channel 218, over surface 221 betweenopenings 225 and 227, and then through channel 220 with free end 30extending from opening 226. The tortuous path aids in securement ofdevice 8.

In FIG. 12B, rather the channel opening on surface 221 being on the sameside, a retaining element 210 b defines two angled channels 218 a, 220 aeach having a channel end 225 a, 227 a, respectively, on opposite sidesof surface 221. Suture 10 thus wraps part way around element 210 b toaid in securement of device 8.

Referring to FIG. 12C, rather than positioning the retaining element onsuture 10 after suture 10 exits from fixation member 18, here retainingelement 210, 210 a, or 210 b is positioned along suture 10 between theportions of suture 10 passing through fixation member 18.

Retaining elements 210, 210 a, 210 b are slidably received on suture 10.In the embodiments of FIGS. 12-12B, the retaining element slides oversuture 10, changing position relative to fixation member 18, while inthe embodiment of FIG. 12C, suture 10 slides within the retainingelement with the position of the retaining element being relativelyunchanged relative to fixation member 18.

Referring to FIG. 13, device 8 can be secured to tissue 14 using asimple overhand knot 230. Knot 230 is first tied in free end 30 ofsuture 10 and pushed, in the direction of arrow 240, through tissue 14and against fixation member 18, as shown in dashed line. Referring toFIGS. 13A and 13B, knot 230 includes three crossing points, labeled, 230a, 230 b, and 230 c. When under tension, T, knot 230 tends to tightenupon itself, rather than slide in the direction of arrow 240 making itdifficult to advance knot 230 along suture 10. To enable tension, T, tobe applied to suture 10 at the same time knot 230 is advanced in thedirection of arrow 240, a knot pusher 250 is used. Knot pusher 250 isconfigured to keep suture at crossing points 230 a, 230 b, and 230 cfrom touching, such that knot 230 does not tighten upon itself undertension, T. This permits knot 230 to slide along the tensioned suturewhen knot pusher 250 is advanced in the direction of arrow 240.

Knot pusher 250 has a cylindrical body 252 and an end post 254. Body 252defines a first groove 254 and a second groove 256 on one surface, and athird groove 258 that is an extension of groove 256 on an oppositesurface. Grooves 254 and 256 form and X pattern, and grooves 256 and 258define a loop 260 extending around body 252. The three grooves differ indepth, with groove 256 being the shallowest and groove 258 being thedeepest. Thus, when suture 10 is formed into an overhand knot andpositioned within grooves 254, 256, and 258, the suture at crossingpoints 230 a, 230 b, and 230 c does not touch. Once knot 230 is advancedagainst fixation member 18, knot pusher 250 is removed by pullingretrograde on the knot pusher. To aid in removal of knot pusher 250, atube (not shown) can be advanced over knot pusher 250 between the knotpusher and the suture. As the tube is advanced past suture crossingpoint 230 a, the suture is stripped from knot pusher 250.

Referring to FIG. 14, one or more additional fixation members 18 a witha slip knot 28 formed in suture 10 can be added to device 8. In use,fixation members 16 and 18 are implanted as described above, with suture10 being tightened to secure fixation members 16 and 18 in place.Additional fixation member 18 a is then implanted and suture 10tightened to secure fixation member 18 a in place. To accommodateadditional fixation members, slot 110 in needle 100 of delivery device99 is extended. To permit access to fixation member 18 by push rod 170,additional fixation members 18 a preferably include a through bore (notshown) for passage therethrough by push rod 170. Push rod 170 preferablyis biased off angle such that when push rod 170 is pulled out of thepassage in fixation member 18 a, the push rod is no longer aligned withthe passage. Subsequent advancement of push rod 170 then engages an endface of fixation member 18 a to push the fixation member toward the tipof the needle 100, rather than back through the passage. Slider 190 ispreferably spring loaded such that after fixation member 18 is pushedout of needle 100, push rod 170 springs back to engage the next fixationmember 18 a.

Referring to FIG. 14A, the positions of fixation member 16 and 18 inneedle 100 can be swapped, with fixation member 18 located in distalregion 112 such that fixation member 18 is implanted in the tissue priorto implantation of fixation member 16. Referring to FIG. 14B, ratherthan suture 10 being fixed to fixation member 16, here suture 10 isattached to fixation member 16 the same as the attachment to fixationmember 18, such that a second slip knot 28 a is formed and a second freeend 30 a of suture extends from fixation member 16. To secure fixationmembers 16 and 18, both ends 30 and 30 a of suture 10 are pulled.

Referring to FIG. 15, in an application for securing soft tissue 262 tobone 264, a suture 266 is attached to fixation members in the form of afirst anchor member 270 and a second anchor member 272. Members 270, 272are, for example, TAG WEDGE bone anchors available from Smith & Nephew,Inc. Endoscopy Division, Andover, Mass. Other bone anchors known in theart can be employed. Suture 266 has a first end 274 fixed to anchormember 270, a second free end 276, and a slip knot 268, formed asdescribed above for slip knot 28. Suture 266 preferably passes through aseparate suture loop 278, rather than through 272 itself. Suture loop278 acts as a good pulley allowing suture 266 to slide relative tosuture loop 278.

In use, the user forms bone holes 280, 282 in bone 264. The user thenimplants anchor member 270 in bone hole 280, with suture 266 alreadythreaded as shown, followed by implanting anchor member 272 in bone hole282. The user then pulls on free end 276 of suture 266, which bringssoft tissue 262 against bone 264. Slip knot 268 limits loosening ofsuture 266. By using suture loop 278, suture 266 is not located withinbone hole 282 in use thus limiting the possibility of trapping suture266 against wall 284 of bone hole 282. If suture 266 were trapped inbone hole 282, pulling free end 276 of suture 266 would not result inshortening the length of suture between anchors 270, 272, which acts tosecure soft tissue 262 against bone 264.

Referring to FIGS. 16A-16C, a wound closure device 1010 includes a firstsuture anchor 1012, a second suture anchor 1014, and a flexible member,e.g., suture 1016 that connects anchor 1012 to anchor 1014. The sutureis tied to the first anchor with a conventional knot, but movablyattached to the second anchor, allowing a surgeon to shorten the lengthof suture between the anchors, and thereby close a wound. First anchor1012 has a generally solid cylindrical body 1018 extending axially froma distal surface 1019 a to a flat proximal surface 1019 b. To facilitatepassage of first anchor 1012 into tissue, both an upper portion 1022 aand a lower portion 1022 b of surface 1019 a are beveled relative to theaxis of cylindrical body 1018, forming a rounded distal tip 1022 c.Upper portion 1022 a is beveled at an angle α relative to the axis ofcylindrical body 1018, and lower portion 1022 b is beveled at an angle βrelative to the axis.

Attached to cylindrical body 1018 is a fin-shaped projection 1020 thatextends from upper portion 1022 a of distal surface 1019 a to proximalsurface 1019 b. Fin 1020 defines two horizontally transverse holes, 1024a and 1024 b. Suture 1016 is attached to first anchor 1012 by passingthe suture through hole 1024 a in a first direction (e.g., out of thepage in FIG. 16A), through hole 1024 b in a second direction (e.g., intothe page in FIG. 16A), and then forming a conventional knot 1025 nearfin 1020. Conventional knot 1025 rigidly fixes suture 1016 to the firstanchor.

Second anchor 1014 has a distal surface 1029 a, a proximal surface 1029b, and a generally cylindrical body 1028 extending axially from surface1029 a to surface 1029 b. Attached to body 1028 is an appendage 1026.Appendage 1026 is generally L-shaped in cross-section, and extends alongan axial length of body 1028, from surface 1029 a to surface 1029 b.

Distal surface 1029 a of anchor 1014 is beveled in a manner similar toanchor 1012: an upper portion 1031 a of surface 1029 a forms an angle θrelative to an axis of body 1028, and a lower portion 1031 b of surface1029 a forms an angle φ relative to the body's axis, forming a roundeddistal tip 1031 c. Proximal surface 1029 b of anchor 1014 is flat.

The L-shape of appendage 1026 is formed by two perpendicular sections: astem 1036 attached to cylindrical body 1028 along an axial length of thebody, and a base 1032 attached to the stem. Base 1032 defines avertically transverse hole 1030, and stem 1036 defines two horizontallytransverse holes 1034 a and 1034 b. Holes 1034 a and 1034 b areperpendicular to hole 1030, but all three holes pass through anchor 1014in a direction generally parallel to sides 1029 a and 1029 b.

Each of the three holes 1034 a, 1034 b, and 1030 connect the exterior ofanchor 1014 to an interior, partially enclosed, protected region 1039.Region 1039 is defined by base 1032, an interior surface 1037 of stem1036, and a concave groove 1035 within cylindrical body 1028. Groove1035 extends axially across body 1028, along the line where interiorsurface 1037 connects to body 1028.

Suture 1016 is movably attached to second anchor 1014 with a one-wayknot 1040. One-way knot 1040 includes a first portion of suture 1016that forms a loop 1042, and a second portion of suture that passesaround body 1028 and through the loop. Loop 1042 is formed within theprotective region 1039 defined by groove 1035, surface 1037, and base1032. Region 1039 acts to separate loop 1042 from tissue when device1010 is implanted within tissue, preventing the tissue from interferingwith the sliding action of one-way knot 1040.

To form one-way knot 1040, suture 1016 is first passed from an exteriorof anchor 1014, through hole 1034 a into region 1039, and then back outhole 1034 b to the exterior, forming loop 1042 within region 1039. Thesuture is then passed over the rounded, exterior surface 1041 ofcylindrical body 1028, back into region 1039, through loop 1042, andthen to the exterior through hole 1030. Suture 1016 terminates at a freeend 1044.

One-way knot 1040 allows the length of suture between first anchor 1012and second anchor 1014 to be shortened, but not lengthened. A surgeoncan shorten the length of suture between the anchors by pulling on freeend 1044, which draws additional suture in the direction of the arrowsin FIG. 16A, through holes 1030, 1034 b, and 1034 a, thereby reducingthe length of suture between anchors 1012 and 1014. If, however, thesurgeon attempts to lengthen the distance between the anchors, e.g., bypulling first anchor 1012 away from second anchor 1014 (i.e., pullingsuture 1016 in the opposite direction of the arrows), then loop 1042squeezes portion 1046 of suture 1016 against an interior compressionsurface 1043 of stem 1036, preventing further lengthening of thedistance between the anchors.

If suture 1016 is a braided suture, as opposed to a smooth suture, thensuture 1016 should be threaded through second anchor 1014 in aparticular direction. Referring to FIG. 16D, a braided suture 1016 a isformed from numerous threads 1017 a braided from left to right in FIG.16D. Braided suture 1016 a slides more easily if it is pulled in thedirection of braiding (i.e., in the direction of arrow S in FIG. 16D)than if it is pulled against the braiding (in the direction of arrow L).Thus, if suture 1016 is a braided suture, then suture 1016 should bethreaded through second anchor 1014 in the direction of braiding. Ifthreaded in the direction of braiding, the suture will slide more easilyin the direction of the arrows in FIG. 16A, and less easily in thedirection opposing the arrows.

The cylindrical portions of anchors 1012 and 1014 are sized and shapedto fit within a hollow bore of a needle (described below), facilitatingarthroscopic implantation of device 1010. For example, cylindrical body1018 has a diameter D₁ of about 0.04 inches, and cylindrical body 1028has a diameter D₂ approximately equal to diameter D₁. Fin-shapedprojection 1020 and L-shaped appendage 1026, however, are configured toprotrude through a longitudinal slit in the needle. Delivery of device1010 using a hollow needle is described below, with reference to FIGS.20A-20D and 21A-21D.

First anchor 1012 has an overall axial length L₁ of, e.g., about 0.19inches, and fin 1020 has a height H₁ of, e.g., about 0.03 inches. Secondanchor 1014 has an overall axial length L₂ of, e.g., about 0.22 inches,a width W₂ of, e.g., about 0.06 inches, and a height H₂ of, e.g., about0.07 inches. Angle α is, e.g., about 30 degrees, angle β is, e.g., about40 degrees, angle θ is, e.g., about 30 degrees, and angle φ is, e.g.,about 40 degrees.

Anchors 1012 and 1014 are made from rigid, biocompatible materials, suchas polyethylene, an acetal, or polypropylene. Alternatively, the anchorscan be made from resiliently deformable materials, as described inHayhurst, supra, or from bioabsorbable materials. Anchors 1012 and 1014are preferably unitary, injection molded pieces, but can also bemanufactured by other methods.

FIG. 17 illustrates the use of wound closure device 1010 to repair atorn meniscus 1050. Meniscus 1050 is a C-shaped, rubbery,shock-absorbing structure located between the tibia and femur inside theknee. Meniscus 1050 has a tear 1052 that unnaturally separates distalmeniscal tissue 1054 from proximal tissue 1056. A width W_(M) ofmeniscus 1050, as measured from points 1060 a and 1060 b to an exteriorsurface 1058 of the meniscus is, e.g., about 0.25 inches.

When device 1010 is implanted within meniscus 1050, both anchors 1012and 1014 abut surface 1058, separated by a distance of, e.g., about 1cm. Suture 1016 passes from first anchor 1012, into distal tissue 1054,across tear 1052, and emerges from proximal tissue 1056 at point 1060 a.Suture 1016 then passes again into proximal tissue 1056 at point 1060 b,again traverses tear 1052, and emerges out surface 1058, where itattaches to second anchor 1014 via one-way knot 1040. From second anchor1040, suture 1016 passes again into distal tissue 1054, traverses tear1052, and emerges from proximal tissue 1056 at or near point 1060 b.Free end 1044 of suture 1016 emerges from proximal tissue 1056.

Referring to FIGS. 17, 18A, and 18B, once device 1010 is implanted, asurgeon can close tear 1052 by pulling on free end 1044 of suture 1016.When the surgeon pulls on free end 1044, four separate movements occurin succession. First, friction between suture 1016 and body 1028 rotatessecond anchor 1014 until a lower surface 1033 of base 1032 is flushagainst meniscal surface 1058, as shown in FIG. 18A. Second, tension insuture 1016 pulls the center of fin 1020 towards surface 1058, causingfirst anchor 1012 to align against surface 1058 transversely to theportion of suture 1016 that exits anchor 1012, with both fin 1020 andthe axial length of body 1018 pressing against meniscal surface 1058.Third, continued pulling on free end 1044 draws additional suturethrough holes 1030, 1034 b, and 1034 a, via knot 1040, in the directionof the arrows of FIG. 16A, lengthening free end 1044 and shortening thelength of suture between anchors 1012 and 1014. Shortening the length ofsuture between anchors 1012 and 1014 increases the tension in suture1016 between the anchors, which pulls distal tissue 1054 and proximaltissue 1056 together, closing tear 1052. Since loop 1042 remains withinprotected region 1039 as the surgeon pulls on free end 1044, base 1032separates loop 1042 from tissue, and suture 1016 does not become wedgedbetween tissue and anchor 1014 when the surgeon pulls on the suture'sfree end. Once tear 1052 has been closed, one-way knot 1040 prevents thetwo anchors from pulling apart, and prevents the tear from re-opening.

The final successive movement occurs when the surgeon releases free end1044, after closing tear 1052. When the surgeon releases the free end,the tension in suture 1016 between the two anchors pulls body 1028 ofanchor 1014 away from free end 1044, causing second anchor 1014 torotate in the direction of arrow R (FIG. 18B), until body 1028 abutsmeniscal surface 1058, trapping a portion 1062 of suture 1016 betweenbody 1028 and surface 1058. (For clarity, suture 1016 is shown spacedslightly from body 1028 and stem 1036 in FIG. 18B. In actuality, suture1016 is flush against the surfaces of anchor 1014 after suture 1016 istensioned by the surgeon.)

When second anchor 1014 is in its final position, shown in FIG. 18B,suture 1016 is locked in place. The length of suture between anchors1012 and 1014 cannot be increased, because loop 1042 of one-way knot1040 presses portion 1046 of the suture against surface 1043 of stem1036. In addition, the length of suture between the anchors resistsbeing further shortened, since portion 1062 of suture 1016 is wedgedbetween body 1028 and surface 1058 of the meniscus.

Wound closure device 1010 is preferably deployed within meniscus 1050arthroscopically, using a hollow needle 1070. Referring to FIG. 19,hollow needle 1070 defines a bore 1072 and an open distal tip 1074. Thediameter D_(B) of bore 1072 is slightly larger than diameter D₁ of body1018 of first anchor 1012, and diameter D₂ of body 1028 of second anchor1014, allowing body 1018 and body 1028 to fit slidably within the bore.Needle 1070 also includes a longitudinal slit 1076 through a wall of theneedle. Slit 1076 extends proximally from open tip 1074, andcommunicates with bore 1072. Slit 1076 is sized and shaped to allow fin1020 of first anchor 1012 and L-shaped appendage 1026 of second anchor1014 to protrude from needle 1070.

Needle 1070 also includes a plunger 1080. Plunger 1080 enters bore 1072through a proximal opening 1082 in needle 1070, and extends to proximalsurface 1019 b of first anchor 1012. Plunger 1080 passes by secondanchor 1014 by sliding along groove 1035. When plunger 1080 ispositioned as shown in FIG. 19, sliding plunger 1080 in the direction ofarrow A pushes first anchor 1012 distally, but does not move secondanchor 1014.

Prior to surgery, suture 1016 is attached to anchors 1012 and 1014, inthe manner described above with reference to FIG. 16A. The two anchors1012 and 1014 are then loaded into bore 1072 of needle 1070. Secondanchor 1014 is loaded first, by inserting cylindrical head 1028 intobore 1072, through open tip 1074, such that appendage 1026 protrudesthrough slit 1076. Second anchor 1014 is pushed proximally into slit1076, until stem 1036 abuts a proximal surface 1077 of the slit. Next,first anchor 1012 is loaded into the distal most position in needle 1070by inserting cylindrical body 1018 through tip 1074, into bore 1072,such that fin 1020 protrudes through slit 1076. Both anchors 1012 and1014 are loaded with their respective beveled distal surfaces 1019 a and1029 a facing open distal tip 1074.

After the anchors have been loaded, plunger 1080 is inserted into bore1072 through proximal opening 1082. Plunger 1080 is slid past secondanchor 1014 along groove 1035, until a tip 1084 of the plunger abutsproximal surface 1019 b of first anchor 1012.

Attachment of suture 1016 to anchors 1012 and 1014 and loading of theanchors and plunger into needle 1070 can be performed at the time ofmanufacture, i.e., pre-loaded, or immediately prior to surgery.

During surgery (or prior to surgery), the surgeon first pushes plunger1080 in the direction of arrow A to separate anchors 1012 and 1014within bore 1072. The surgeon pushes the plunger until the anchors areseparated by at least a distance L, as shown in FIG. 19, where L isgreater than width W_(M) of meniscus 1050. Distance L is, e.g., about0.35 inches.

Referring to FIGS. 17 and 20A-20D (not to scale), the surgeon nextpushes needle 1070 through meniscus 1050, in the direction of arrow A,until fin 1020 of first anchor 1012 passes entirely through exteriorsurface 1058 of the meniscus. As the surgeon pushes needle 1070 throughthe tissue, he or she holds plunger 1080 steady, to prevent anchor 1012from sliding in the direction of arrow B as the needle is pushed throughthe meniscal tissue. Since the separation distance L is greater than thewidth W_(M) of meniscus 1050, second anchor 1014 does not enter themeniscus at this point in the procedure.

The surgeon next forces first anchor 1012 out of needle 1070 through tip1074 by pushing plunger 1080 in the direction of arrow A, and then seatsanchor 1012 against surface 1058 of the meniscus by pulling on free end1044 of suture 1016. Once anchor 1012 has been seated, needle 1070 ispulled in the direction of arrow B, back through meniscus 1050, acrosstear 1052, and out the hole at point 1060 a (FIG. 20B).

The surgeon then reinserts needle 1070 into meniscus 1050 at point 1060b, and again passes the needle through the meniscus in the direction ofarrow A, across tear 1052, until tip 1074 passes through surface 1058.To eject second anchor 1014, the surgeon withdraws plunger 1080 in thedirection of arrow B until tip 1084 of the plunger is proximal tosurface 1029 b of anchor 1014. The surgeon then maneuvers plunger 1080until tip 1084 contacts surface 1029 b, and then pushes the plunger inthe direction of arrow A, forcing second anchor 1014 through tip 1074.Plunger 1080 and needle 1070 are then fully withdrawn in the directionof arrow B, leaving both anchors 1012 and 1014 resting against surface1058, as shown in FIG. 20D. The surgeon can then tension suture 1016,positioning the anchors against surface 1058 and closing tear 1052, bypulling on free end 1044, as described above with reference to FIG. 17.

Alternative deployment methods are possible. For example, device 1010can be extracted from needle 1070 by engaging fin 1020 with surface1058, rather than by using a plunger 1080. Referring to FIG. 21A-21D(not to scale), in this embodiment, plunger 1080 is not passed throughgroove 1035 to first anchor 1012. Instead, tip 1084 of plunger 1080always remains proximal to anchor 1014.

When the two anchors are loaded into bore 1072 of needle 1070, a spacer1086 is placed between the anchors. Spacer 1086 is a simple cylindricalbar, preferably made from a material that degrades quickly in the body,such as salt. Spacer 1086 has a longitudinal length L_(S) greater thanwidth W_(M) of meniscus 1050. Length L_(S) is, e.g., about 0.35 inches.

During surgery, the surgeon first pushes needle 1070 through meniscus1050, in the direction of arrow A, until fin 1020 passes entirelythrough exterior surface 1058 of the meniscus (FIG. 21A). As the surgeonpushes needle 1070 through the tissue, surface 1077 of slit 1076 engagesstem 1036 of anchor 1014, preventing the two anchors and the spacer fromsliding in the direction of arrow B within bore 1072. (In addition, thesurgeon can hold plunger 1080 steady to prevent the two anchors fromsliding in the direction of arrow B.)

The surgeon next pulls the needle in the direction of arrow B, backthrough meniscus 1050, across tear 1052, and out the hole at point 1060a (FIG. 21B). As the surgeon withdraws the needle, fin 1020 engagessurface 1058, and first anchor 1012 is pulled out of needle 1070,through tip 1074. As before, the surgeon then seats anchor 1012 againstsurface 1058 by pulling on free end 1044 of suture 1016. Since spacer1086 is larger than width W_(M) of meniscus 1050, the spacer preventssecond anchor 1014 from entering meniscus 1050, and therefore preventssecond anchor 1014 from also being pulled out of needle 1070 as needle1070 is pulled in the direction of arrow B.

Next, the surgeon reinserts needle 1070 into meniscus 1050 at point 1060b, and again passes the needle through the meniscus in the direction ofarrow A, across tear 1052, until tip 1074 passes through surface 1058.The surgeon then pushes plunger 1080 in the direction of arrow A,ejecting both spacer 1086 and second anchor 1014 out of needle 1070through tip 1074 (FIG. 21C). The needle is then fully withdrawn frommeniscus 1050, in the direction of arrow B, leaving both anchors 1012and 1014 resting against surface 1058, as shown in FIG. 21D. The surgeonthen pulls on free end 1044 to position the anchors and close the tear,as described above. Spacer 1086 can either be removed by the surgeon, orleft within the body to degrade.

In another alternative deployment method, a modified wound closuredevice is deployed in meniscus 1050 in reverse, second anchor first.Referring to FIG. 22A, a modified wound closure device includes a firstanchor 1112 that has a beveled face 119 a, but lacks a fin. Anchor 1112has an axial, generally cylindrical body 1118 that defines twotransverse holes 1124 a and 1124 b. Suture 1016 is attached to anchor1112 by threading the suture through hole 1124 a in a first direction,through hole 1124 b in a second direction, and then tying a conventionalknot 1125.

Referring to FIGS. 22B-22E (not to scale), in this reverse deploymentembodiment, second anchor 1014 is positioned distally in bore 1072, withfirst anchor 1112 directly proximal. Tip 1084 of plunger 1080 residesimmediately proximal to first anchor 1112 in bore 1072. In operation,the surgeon first pushes needle 1070 through meniscus 1050, in thedirection of arrow A, until tip 1074 passes through surface 1058. Thesurgeon then pushes plunger 1080 in the direction of arrow A far enoughto force second anchor 1014 through tip 1074, but not far enough toeject first anchor 1112.

After anchor 1014 has been ejected, the surgeon pulls the needle in thedirection of arrow B, back through meniscus 1050, across tear 1052, andout point 1060 a (FIG. 22C). Since first anchor 1112 does not include afin, it does not protrude through slit 1076, and does not engage tissuewhen the needle is pulled in the direction of arrow B. Next, the surgeonreinserts needle 1070 into the meniscus at point 1060 b, and againpasses the needle through meniscus 1050 in the direction of arrow A,across tear 1052, until tip 1074 passes through surface 1058. Thesurgeon then ejects first anchor 1112 by pushing plunger 1080 in thedirection of arrow A, (FIG. 22D), and withdraws needle 1070 frommeniscus 1050. The surgeon then positions the anchors and closes tear1052 by pulling on free end 1044 (FIG. 22E), as described above.

Alternative configurations of second anchor 1014 and one-way knot 1040are possible.

For example, referring first to FIGS. 23A and 23B, suture 1016 can bethreaded through second anchor 1014 so that the loop is located againstan exterior surface 1637 of stem 1036, rather than within region 1039.In this embodiment, suture 1016 is threaded through second anchor 1014by first passing the suture around base 1032, into region 1039, and thenout of region 1039 through hole 1034 a. The suture then passes back intoregion 1039 through hole 1034 b, forming a loop 1642 adjacent surface1637. After forming the loop, the suture passes through hole 1030 to theexterior, and then through loop 1642, terminating at free end 1644.

When the surgeon pulls free end 1644 of suture 1016, the anchor rotatesuntil surface 1637 faces surface 1058 of meniscus 1050 (FIGS. 17 and18A-18B). Cylindrical body 1028 causes part of surface 1637 to remainelevated above surface 1058, creating a small gap 1639 that containsloop 1642. Loop 1642, therefore, does not become wedged between tissueand surface 1637 when the surgeon pulls free end 1644 to tension thesuture.

Referring to FIG. 24, second anchor 1214 has a structure similar toanchor 1014, except that anchor 1214 lacks a base 1032. Anchor 1214includes a cylindrical body 1228 and a stem 1236 that define awedge-shaped, partially enclosed region 1239 therebetween. Stem 1236defines two holes, 1234 a and 1230, and body 1228 defines one transversehole 1234 b. Holes 1234 a and 1230 are generally parallel, and are bothgenerally perpendicular to hole 1234 b. A suture 1216 passes from afirst anchor (not shown) through hole 1234 a into region 1239, and thenthrough hole 1234 b to the exterior of the anchor, forming a loop 1242within region 1239. The suture then wraps around body 1228 back intoregion 1239, through loop 1242, and out of region 1239 through hole1230, terminating at free end 1244. Alternatively, suture 1216 can wraparound body 1228 two or more times before passing back into region 1239.

As in the previous embodiments, pulling on free end 1244 tensions suture1216 and shortens the length of suture between the anchors. Pulling onsuture 1216 in an opposite direction, however, causes loop 1242 to pressa portion 1246 of the suture against a compression surface 1243. Sinceloop 1242 is located within protected region 1239, and is thereforespaced from the meniscal surface, loop 1242 does not become wedgedbetween tissue and the anchor when the surgeon tensions suture 1216.Unlike the previous embodiments, however, anchor 1214 does not rotateafter the surgeon tensions the suture and releases free end 1244.

Referring to FIG. 25, second anchor 1314 includes a generallycylindrical body 1328 and an offset, generally rectangular appendage1326. Appendage 1326 and body 1328 define a partially protected region1339. As with anchor 1014, a front surface 1329 a of anchor 1314 isbeveled.

Appendage 1326 defines three holes, 1330, 1334 a, and 1334 b. Holes 1334a and 1330 are generally straight, while hole 1334 b defines an arcthrough an inside of appendage 1326. A suture 1316 passes from a firstanchor (not shown) through straight hole 1334 a into region 1339. Suture1316 then passes out of region 1339 through arc-shaped hole 1334 b,forming a loop 1342 within region 1339. The suture then wraps around acorner 1320 of body 1326, passes through loop 1342, and through hole1330, terminating at free end 1344. As with the embodiments of FIGS. 16,22A-22B, and 23, pulling on free end 1344 shortens the length of suturebetween the anchors, but pulling on suture 1316 in an opposite directioncauses loop 1342 to squeeze a portion 1346 of the suture against acompression surface 1343 of appendage 1326, preventing further movement.Like the embodiment of FIG. 23, anchor 1314 does not rotate after thesuture is tensioned and released.

Referring to FIG. 26, second anchor 1414 includes a generallycylindrical body 1428 extending from a beveled distal surface 1429 a toa flat proximal surface 1429 b. A generally rectangular appendage 1426also extends from surface 1429 a to surface 1429 b. Rectangularappendage 1426 is attached to body 1428 along the long side of therectangle, and is centered along an axial length of body 1428. Body 1428and appendage 1426 define a protected region 1439.

Appendage 1426 defines two holes, 1434 a and 1430, and body 1428 definestwo transverse holes, 1434 b and 1434 c. Hole 1434 b is located entirelywithin body 1428, but hole 1434 c is located at a juncture 1492 betweenbody 1428 and appendage 1426. Holes 1434 a and 1430 are generallyparallel, and are both generally perpendicular to holes 1434 b and 1434c.

A suture 1416 extends from a first anchor (not shown), through hole 1434a into region 1439, and then out of region 1439 through hole 1434 b,forming a loop 1442 within region 1439. The suture then passes back intoregion 1439 through hole 1434 c, through loop 1442, and out of region1439 through hole 1430, terminating at free end 1444.

As with the other described second anchor embodiments, pulling on freeend 1444 tensions suture 1416 and shortens the length of suture betweenthe anchors, but pulling on suture 1416 in an opposite direction causesloop 1442 to squeeze a portion 1446 of the suture against a compressionsurface 1443 of appendage 1426, preventing further movement. Region 1439is separated from the meniscal tissue by body 1428, preventing loop 1442from wedging between anchor 1414 and tissue when the surgeon pulls onfree end 1444. Anchor 1414 does not rotate after the surgeon tensionsand releases the suture.

Referring to FIG. 27, second anchor 1514 includes a generallycylindrical body 1528 and an appendage 1526. Both body 1528 andappendage 1526 extend from a beveled distal surface 1529 a to a flatproximal surface 1529 b. Appendage 1526 includes a stem 1536 attached tobody 1528, and a head 1532 attached to stem 1536. Stem 1536 isrectangular in cross-section and head 1532 is D-shaped in cross-section,giving appendage 1526 a mushroom-shaped cross-section. Stem 1536, head1532, and body 1528 define a partially enclosed, protected region 1539.

Stem 1536 defines two transverse holes 1534 a and 1534 b, and body 1528defines a single transverse hole 1530 located at a juncture 1592 betweenbody 1528 and stem 1536. A suture 1516 passes from a first anchor (notshown), through hole 1534 a into protected region 1539, and then out ofregion 1539 through hole 1534 b, forming a loop 1542 within region 1539.Suture 1516 then passes around D-shaped head 1532 through a transversegroove 1594 in head 1532, back into region 1539, through loop 1542, andout hole 1530, terminating at free end 1544. As with the other describedembodiments of the second anchor, pulling on free end 1544 shortens thedistance between the two anchors, but pulling on suture 1516 in anopposite direction causes loop 1542 to squeeze a portion 1546 of thesuture against a compression surface 1543 of stem 1536, preventingfurther movement. That loop 1542 is located within region 1539 preventsthe loop from becoming wedged between the anchor and tissue when thesurgeon pulls on free end 1544. Anchor 1514, like anchors 1214, 1314,and 1414, does not rotate after the surgeon tensions and releases thesuture.

Referring to FIGS. 28A-28D and FIGS. 29-31, the second anchor can have aT shape or a crescent shape, and can be deployed at a surface of themeniscus or inter-body. Referring to FIGS. 28A and 28B, second anchor1730 has a T-shape. The base 1732 of the T defines three through-holes,1734 a, 1734 b, and 1734 c, and the stem 1736 of the T is configured topenetrate meniscal tissue. Stem 1736 is offset from base 1732 so thatthe stem does not block hole 1734 b. Referring to FIGS. 28C and 28D,second anchor 1814 has a flat, generally circular proximal surface 1836,and a rounded distal surface 1838, giving the anchor a generallyhemispherical or “crescent” shape. (Alternatively, surface 1836 can beconcave.) Anchor 1814 defines three through-holes, 1830, 1834 a, and1834 b. The holes pass in an axial direction from the anchor's proximalcircular surface 1836 to its distal rounded surface 1838.

FIG. 29 illustrates deployment of a device 1810 that has acrescent-shaped second anchor 1814, and a “pulley” anchor 1813. Pulleyanchor 1813 does not act as a dead-end for a suture, nor does it includea one-way knot. Instead, pulley anchor 1813 includes two through-holes,1824 a and 1824 b. A suture 1816 passes through hole 1824 a in a firstdirection, and then through hole 1824 b in a second direction, such thatsuture 1816 can slide over pulley anchor 1813 in either direction.Pulley anchor 1813 can have the shape and structure of anchor 1012(i.e., the holes are located on a fin), the simple cylindrical structureof anchor 1112 of FIG. 22A, or numerous other structures.

In operation, anchors 1813 and 1814 are deployed using, e.g., a hollowneedle 1070, such that anchor 1814 is positioned on a proximal side ofmeniscus 1050, and anchor 1813 is deployed against distal surface 1058.When deployed, suture 1816 passes through hole 1834 a of crescent-shapedanchor 1814 in a generally proximal direction (arrow P), from roundedsurface 1838 to circular surface 1836, and then through hole 1834 b in agenerally distal direction (arrow D), forming a loop 1842. From loop1842, the suture passes through meniscal tissue, through hole 1824 a ofpulley anchor 1813, through hole 1824 b of anchor 1813, and back throughmeniscal tissue to the crescent shaped anchor. The suture then passesthrough loop 1842, terminating at free end 1844. The opposite end 1845of suture 1816 includes a knob or a knot 1847 that prevents end 1845from passing through hole 1834 a. Thus, suture 1816 begins at anchor1814, in addition to forming the one-way knot at anchor 1814.

Referring to FIG. 30, rather than beginning at anchor 1814, the suturecan be affixed to a first anchor 1012. In FIG. 30, a device 1811includes a first anchor 1012 and crescent-shaped second anchor 1814.Suture 1816 passes through holes 1024 a and 1024 b of anchor 1012,forming a knot 1025 as shown in FIG. 16A. From knot 1025, suture 1816passes through meniscal tissue and then through holes 1834 a and 1834 bof anchor 1814, forming loop 1842. From loop 1842, the suture passesback through meniscal tissue to first anchor 1012, and then through afixed loop 1843 located between knot 1025 and first anchor 1012. Thesuture then passes back through meniscal tissue, through hole 1830 ofanchor 1814, and through loop 1842, terminating at free end 1844.

When a surgeon pulls on free end 1844 in device 1811, the mechanicaladvantage is 3:1, since suture 1816 passes between the two anchors threetimes. By comparison, in device 1810, the mechanical advantage is 2:1.

Referring to FIG. 31, the crescent shaped anchor 1814 of device 1810 canbe deployed inter-body (i.e., embedded within meniscal tissue), ratherthan against a surface of the meniscus. In this deployment method,device 1810 is deployed in the manner described above with reference toFIG. 29, or using another deployment method. After positioning theanchors and tensioning free end 1844, however, the surgeon pushes anchor1814 into the meniscal tissue, using, e.g., a needle. To facilitatepushing anchor 1814 into the tissue, a point 1817 of anchor 1814 can besharp.

Other types of second anchors described herein, whether or not theyinclude a sharp point, can also be positioned inter-body.

In each of the described embodiments of the second anchor, the one-wayknot can be left “loose” until after both the first and second anchorsare positioned against the meniscus. In such an embodiment, the suturewould be very long, e.g., more than 12 cm long, such that the one-wayknot includes considerable slack, and the loop portion of the knot isaccessible to the surgeon's fingers. In this embodiment, the surgeon canposition the first and second anchors against backside 1058 by pullingon both the free end and the loop itself. Once the anchors aresatisfactorily positioned, the surgeon tightens the knot by pulling onthe free end.

The second anchor can employ one-way tightening schemes other than a“one-way knot.” For example, referring to FIG. 32, a device 1650includes first anchor 1012, a second anchor 1652, and two sutures 1616and 1654. Second anchor 1652 has a generally cylindrical shape, anddefines two through-holes 1656 and 1658. When anchors 1012 and 1652 arepositioned against backside 1058 of meniscus 1050, suture 1616 passesfrom first anchor 1012, through holes 1060 a and 1060 b in the meniscus,and then through holes 1656 and 1658 of anchor 1652, terminating at freeend 1660. Suture 1616 does not form a one-way knot at second anchor1652. Instead, suture 1616 simply passes through holes 1656 and 1658 insuccession, such that anchor 1652 acts as a pulley anchor.

The second suture, suture 1654, passes only through hole 1656 of anchor1652, and through hole 1060 b of the meniscus. A portion 1662 of suture1654, distal to hole 1656, is thicker than the remainder of suture 1654.This thicker portion 1662 cannot pass through hole 1656. (The thicknessof portion 1662 is exaggerated in FIG. 32.)

In operation, a surgeon deploys the two anchors as described above withrespect to other embodiments, and then pulls on free end 1660 of suture1616 to position the anchors against backside 1058 and close the tear inthe meniscus. Once suture 1616 is tensioned to the surgeon'ssatisfaction, the surgeon pulls on suture 1654 in the proximal direction(arrow P), until a segment of portion 1662 wedges into hole 1656.Portion 1662 wedges suture 1616 in place within hole 1656, preventingthe length of suture 1616 between the two anchors from increasing, andthereby locking the two anchors in place.

Modifications of other portions of wound closure device 1010 are alsopossible. For example, the fin-shaped projection 1020 of the firstanchor need not have the shape shown in the figures. Other types ofprojections capable of protruding through a needle opening and engagingtissue can be used. In addition, as described above with reference toFIGS. 21A, the first anchor need not include any projection, but caninstead be a simple cylinder defining holes for affixation of thesuture.

Instead of attaching the suture to the first anchor using a conventionalknot 1025, the suture can be welded or glued to the anchor, or can bespliced.

Referring to FIG. 33A, the first anchor need not include an extended,cylindrical body, but can instead have a button-shaped body.Button-shaped first anchor 1712 includes a circular distal side 1719 aand a circular proximal side 1719 b. Two axial holes 1724 a and 1724 bpass from side 1719 a to side 1719 b. A suture 1716 is attached toanchor 1712 by passing through hole 1724 a in a first direction, throughhole 1724 b in a second direction, and then forming a conventional knot1725 on the distal side of the anchor.

Referring to FIG. 33B, button-shaped first anchor 1712 is deployedagainst a proximal surface 1796 of meniscus 1050, and second anchor 1014is deployed against surface 1058. Suture 1716 passes from first anchor1712 into proximal tissue 1056 at point 1760, such that knot 1725 islocated within the tissue. From point 1760, suture 1716 passes acrosstear 1052 to second anchor 1014, then through second anchor 1014 in themanner described above with reference to FIG. 16. From second anchor1014, the suture passes back into distal tissue 1054, across tear 1052,and emerges from proximal tissue 1056 at point 1760. The suture thenterminates at free end 1744. As with the embodiments described above,pulling on free end 1744 tensions the suture and closes the tear.

Alternatively, button-shaped anchor 1712 can be deployed on the distalside of the tear adjacent second anchor 1014, using the methodsdescribed above with reference to FIGS. 17, 20A-20D, 21A-21D, and22A-22D.

The second anchor need not include a groove 1035 to allow passage of aplunger. Instead, the second anchor can define an axial through-hole forpassage of the plunger.

Rather than a suture, the first and second anchors can be connected withother types of flexible members.

The wound closure device can include more than two suture anchors. Forexample, in addition to the first and second anchors, the device caninclude a third anchor identical in structure and function to the secondanchor. In operation, after deploying the second anchor against surface1058 of meniscus 1050, the surgeon could again pass the suture acrosstear 1052, adding an additional stitch, and then deploy the third anchoragainst surface 1058. After deploying all three anchors, the surgeonwould pull on the free end of the suture, causing the suture to slideover both the second and third anchors, shortening the length of suturebetween the third and first anchors, and thereby closing the wound.

When more than two anchors are used, one or more of the anchors can be apulley, such as pulley anchor 1813 described above with reference toFIG. 29. For example, the device could include a first anchor 1012, apulley anchor 1813, and a second anchor 1014. The suture would beaffixed to the first anchor, would slide over the pulley anchor, andform a one-way knot at the second anchor.

Depending on the size of the tissue wound, more than three anchors canbe used. The additional anchors can all be pulley anchors, can all besimilar to the second anchor, or can be both additional pulleys andadditional second anchors.

The wound closure devices need not be deployed using a needle, and neednot be deployed arthroscopically. Instead, a surgeon can place theanchors against the tissue during an open procedure.

The wound closure devices can be used to repair tissue wounds other thanmeniscal tears. For example, the devices can be used to repair tears inskin, muscles, and ligaments, and to re-attach tissue to supportstructures, such as bones.

Referring to FIGS. 34-36, a device 308 for repairing a tear 12 in tissue14 includes a suture 310 attached to a single fixation member 326.Fixation member 326 defines through holes 330, 332 for receiving suture310. Suture 310 has a first end 312 attached to suture 310 at point 314(as described above with reference to FIG. 2B) to form a looped end 316remote from fixation member 326, and a second, free end 334.

When implanted in the knee joint, fixation member 326 lies on a surface20 of tissue 14. Looped end 316 is located in tear 12 and extends alongsurface 26 of tissue 14. Suture 310 extends through tissue 14, passingthrough looped end 316 in tear 12, and emerging at tissue surface 20where suture 310 loops through fixation member 326. Suture 310 extendsback through tissue 14, passing through looped end 316 in tear 12 andthrough a slip knot 321 formed in suture 310, and emerging at tissuesurface 26. As described further below, after device 308 is positionedin tissue 14, the user pulls on free end 334 of suture 310, in thedirection of arrow 520, to bring sides 22, 24 of tear 12 together intojuxtaposition (as shown in FIG. 34). Slip knot 321 limits loosening ofsuture 310. Alternatively, looped end 316 is located on surface 20between fixation member 326 and surface 20, as shown in dashed line inFIG. 34.

Referring to FIGS. 37-37B, a delivery device 399 for implanting device308 includes a suture holder 400 and needle 460. Suture holder 400includes a tube 410 defining a lumen 415 through which needle 460extends, a shaft 420, and a distal portion 430. Distal portion 430 has afirst tine 440 defining grooves 445 and 446, and a second tine 450defining grooves 455, 456. Needle 460 has a beveled tip 461 and a slot462 in a top portion 463 of needle 460.

When assembled, fastening member 326 with attached suture 310 ispositioned in slot 462 with suture 310 preformed with looped end 316 andslip knot 321. Slip knot 321 is formed as described above with referenceto FIGS. 2A-2I, though where fixation member 16 is positioned in FIGS.2A-2I, suture 310 is formed as looped end 316 (FIG. 37C). Looped end 316is positioned on suture holder 400 within grooves 445, 446, 455 and 456of tines 440, 450 (FIG. 37B), and extends along a bottom side 480 ofshaft 420. As shown in FIG. 37, delivery device 399 includes a handle451 with a push knob 453 for advancing needle 460 relative to sutureholder 400.

Referring to FIG. 38, in use, the user inserts distal portion 430 ofsuture holder 400 into tear 12 of tissue 14, and then advances needle460 through tissue 14, traversing tear 12, and exiting tissue 14 attissue surface 20. Needle 460 passes between tines 440 and 450, and thusthrough looped end 316 of suture 310 (FIG. 39). The user then retractsneedle 460 from tissue 14 (FIG. 40). The contact of fastening member 326with tissue surface 20 during the retraction of needle 460 acts to pushfastening member 326 out of needle 460 such that fastening member 326remains at surface 20, as described above with reference to FIG. 7.Pulling on free end 334 of suture 310 brings sides 22, 24 of tear 12into juxtaposition. Slip knot 321 secures device 308 in place. Excesssuture 310 can then be cut off.

Referring to FIG. 41, rather than securing device 308 with a slip knot,suture 310 includes a retaining element in the form of a Chinese trap orhand cuff 495, that is, an element that when pulled on, tightens aroundsomething disposed within the element. Free end 334 of suture 310 isslidably received within trap 495. When free end 334 of suture 310 ispulled in the direction of arrow 520 trap 495 is stretched, eventuallygripping suture passing therethrough to secure suture 310 and device308. The retaining element can also take the form of retaining elementsdescribed above with reference to FIGS. 12-12C and 13.

Referring to FIG. 42, a device 799 for repairing tear 12 in tissue 14includes a barbed fastening member 800 and a suture 820. Suture 820 hasan end 810 attached to fastening member 800. Suture 820 is formed inloop 830 with a second end 832 of suture 820 attached to suture 820.Delivery device 399 can be used to deploy device 799 with suture 820being tightened to close tear 12 by pushing fastening member 800 in thedirection of arrow 840, rather than pulling on a free end of suture.Barbed fastening member 800 limits loosening of suture 820.

Referring to FIG. 43, an alternative embodiment of a fixation member 600includes through bores 610, 620 with radiused corners 615 to reducefriction between suture 470 and fixation member 600. Referring to FIG.44, another embodiment of a fixation member 650, which can be used inany of the above embodiments, includes a solid rod 660 with ends 680,690, and a braided suture 670 attached to ends 680, 690. Suture 670forms a loop 700 for receiving suture 10 or suture 310. Loop 700 linesup with suture 10, 310 to act as a pulley and reducing friction betweenthe suture and fixation member.

The fixation members, securement elements, and suture of the aboveembodiments can be formed of a biodegradable material.

Other embodiments are within the scope of the following claims.

1-83. (canceled)
 84. A suture anchor assembly comprising: an anchorcomprising: a top surface and an opposing bottom surface; an elongatedchannel recessed into the bottom surface; and a first passageway and aspaced apart second passageway extending from the top surface to thechannel; a suture comprising a proximal end and an opposing distal end,a portion of the suture between the proximal end and the distal endbeing formed into a loop, the loop being at least partially passedthrough the first passageway, at least one of the proximal end or thedistal end of the suture being passed through the second passageway andthen through the loop such that pulling on the proximal end or thedistal end of the suture that is passed through the loop causes thesuture to selectively lock against the anchor.
 85. A suture anchorassembly as recited in claim 84, wherein the anchor further comprises athird passageway, wherein the proximal end or the distal end of thesuture that is not passed through the loop is passed through the thirdpassageway.
 86. A suture anchor assembly as recited in claim 85, furthercomprising a second anchor, wherein the proximal end or the distal endof the suture that is not passed through the loop is secured to thesecond anchor.
 87. A suture anchor assembly as recited in claim 86,further comprising a channel recessed on the anchor, the channelintersecting with the first passageway and the second passageway.